I wonder if these old [n]mh FAQ things would help? I remember using mhfinddup a LONG time ago.
https://www.mhonarc.org/archive/html/nmh-workers/2008-09/msg00004.html https://lists.gnu.org/archive/html/nmh-workers/2008-09/msg00001.html https://github.com/dscho/nmh/blob/master/docs/FAQ On Mon, May 4, 2020 at 7:23 AM Conrad Hughes <biz_nmh_work...@xrad.org> wrote: > > I know that 'sortm -textfield Subject' will sort messages accoring to > > the subject field. Having run that command, is there a way to then > > delete the first duplicate of each message in the list such that if 1 > > and 2 are duplicates and 6 and 7 are duplicates you would delete messages > > 2 and 7 leaving 1 and 6? > > The attached might be a useful starting point: run it with a directory > name (e.g. ~/Mail) and it'll find everything that looks like an MH mail > file (i.e. its name is a number) and delete any messages with an > already-seen Message-ID — i.e. the second and subsequent copies of any > emails. > > I'd run it on a duplicate of your Mail folder and see what the diffs > look like: biggest issue is that I'm not sure what order it'll do things > in so you may find your preferred copy doesn't get kept — but its output > will be a good starting point for any better version. > > Conrad >